PSTN Calling

Simplify calling with a reliable, cloud-based telephone solution. PSTN Calling, a Skype for Business service, provides a comprehensive phone system that’s managed through your Office 365 subscription.

Now you can add PSTN Calling to your Office 365 Enterprise E5 subscription.
Learn more about Office 365 Enterprise E5

Simplify your systems

PSTN Calling brings the benefits of the cloud to your phone system by shifting your phone infrastructure to Microsoft Office 365.

Elevate your services

Because PSTN Calling is part of Microsoft Office 365, it enables services, security, and support that traditional phone lines can’t match.

Connect your business

With PSTN Calling, you can unify your communications services in Office 365 and integrate calling with your business processes for increased productivity.

PSTN Calling includes:

Business-ready phone

Get started fast with a cloud service that offers the features you expect from traditional phones, such as number porting, emergency calling, toll-free numbers, and flexible calling plans.

Cloud PBX

Manage a PBX in Office 365 to support call-management features such as hold, forward, transfer, and voicemail.

Managed service

Save the time and money you’d otherwise spend to install and maintain an on-premises telephony infrastructure.

Centralized administration

Use the Office 365 admin portal to acquire numbers, assign numbers, and manage users.

Immediate connectivity

Provision phone numbers for all your Office 365 users within minutes via the Office 365 admin portal.

Any device

Enable telephone calls from any device, including IP phones, Skype room systems, PCs, Mac, and mobile devices.

Search and acquire

Easily request and reserve new phone numbers in major cities where PSTN calling is available.

Built-in security

Protect your business with enhanced security features from encryption and security protocols to physical and operational security.

High availability

Office 365 guarantees 99.9% uptime for your phones lines with built-in redundancy and active load balancing.

Call reporting

Run usage reports to review active users, sessions, client device information, and types of activities.

Identity management

Streamline identity management with phone numbers linked to Azure Active Directory identities.

Requirements for PSTN CallingTooltip with information about PSTN calling

Table show details of PTSN Calling plans
 Office 365 Enterprise plans and information on pricing for PSTN calling
Calling Plan Price Tooltip about prices
Total Price Tooltip about total price

Office 365 Enterprise E5

product features and pricing information
No additional requirements

Domestic: {PSTNBizE5Domestic|price}

International: {PSTNBizE5International|price}

Domestic: {PSTNBizE5Domestic|price}

International: {PSTNBizE5International|price}

Office 365 Enterprise E3

product features and pricing information
Cloud PBX ({CloudPBXO365E3|price})

Domestic: {PSTNBizE3Domestic|price}

International: {PSTNBizE3International|price}

Domestic: {PSTNBizE3TotalDomestic|price}

International: {PSTNBizE3TotalInternational|price}

Office 365 Enterprise E1

product features and pricing information
Cloud PBX ({CloudPBXO365E1|price})

Domestic: {PSTNBizE1Domestic|price}

International: {PSTNBizE1International|price}

Domestic: {PSTNBizE1TotalDomestic|price}

International: {PSTNBizE1TotalInternational|price}


See the rates for where you want to call

Get a detailed list of the toll and toll-free rates for your agreement by country and currency. Consumption rates are for charges that are not included in your subscription plan. Tooltip about rate qualifications

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PSTN Calling provides domestic and international calling plans with Skype for Business. Organizations can subscribe to calling plans from Office 365 and use existing phone numbers or get new numbers.

For additional information, see What is PSTN calling?

Yes, customers with Enterprise E1 and E3 can upgrade to PSTN Conferencing and Cloud PBX + PSTN Calling as standalone offers.

While Cloud PBX provides the call control capabilities for end users and the administrative features for IT, it connects to the PSTN through either Microsoft PSTN Calling add-on or to your existing PSTN circuits using Cloud Connectivity.

Yes, in order to use these services, you must have Skype for Business Plan 2, or equivalent E SKU (E1/E3/E5), deployed as a standalone or as a component of Office 365 E1, E3, or E5 suites. To use PSTN Calling, you must also purchase Cloud PBX or E5 (which includes Cloud PBX functionality) as a prerequisite. To use the full Cloud PBX capabilities, including voice mail, you need Exchange Online Plan 2 and the Skype for Business Client.

If you are an Office 365 Enterprise E5 or Cloud PBX customer, you can connect your existing PSTN service provider with Microsoft cloud-based call control. Scenarios are based on whether a customer already has a Skype for Business Server deployed. You can set up a new server pool or use an existing Skype for Business Server deployment to configure it to connect to Cloud PBX functionality that is covered under existing server licensing.

If you don’t have an existing server, you can use a minimal Skype for Business Server deployment through the Cloud Connected Edition that includes four preconfigured Virtual Machines (VMs) deployed on customer-owned Windows Servers. Skype for Business Server roles in VMs are not paid roles and are licensed for use with Cloud PBX.

PSTN Calling is subject to geographical and channel availability. See Countries and regions that are supported for Skype for Business Online PSTN Services for more information.

  • For domestic PSTN Calling plans, each licensed user is allocated the above-stated domestic dial-out minutes pooled at the tenant level.
  • For international PSTN Calling plans, each licensed user is allocated the above-stated domestic dial-out minutes and 600 international dial-out outbound minutes pooled at the tenant level.

For all local and international calls placed to users within the same tenant, peer-to-peer calling is enabled and the call is placed over the Voice Over IP network, meaning that all local and international calls placed within the tenant will not count towards the allocated minutes.

If you are set up for PSTN Consumption billing, when you exceed the PSTN Calling allocated minutes (the total of all minutes associated with users’ assigned licenses pooled at the tenant-level), you will be charged for usage that goes above and beyond the tenant-pooled limits. If you are not set up for Consumption billing, you will lose your service until the minute limits are reset the following month.

No, domestic and international minute allocations are based on a monthly cycle. Any minutes that are unused during one month will not rollover to the next month.

Calls placed to other users whose license resides in the same Office 365 tenant, domestic or international, will not count towards the excessive use limits for PSTN Calling. When calls are placed within the same tenant, reverse number lookup functionality will validate that the call originated in the same tenant, and it will be placed as a peer-to-peer call on the Voice Over IP network, if available.

Domestic calling, per the Skype for Business Online PSTN service use terms, is defined as: “The ability for the user to make calls to numbers located within the country of Office 365 assignment for that user.” In other words, if a US-based user (meaning their Office 365 license is assigned in the US) travels to London, any calls they make back to the US are considered domestic calls.

Consumption billing for PSTN services will launch on June 1, 2016, enabling PSTN Conferencing toll-free dial-in, international dialing for users with PSTN domestic calling, and additional domestic and international calling minutes.

Set-up and management:

  • Customer selects an individual pre-paid balance amount (e.g. $100), minimum balance threshold (e.g. $10), and balance replenishment amounts (e.g. $90).
  • Customer funds their pre-paid balance directly in the Office 365 Portal (as opposed to buying on CPS – SKU on PL).
  • It’s important to establish appropriate replenishment amounts as all payments made to fund prepaid balance are valid for one year.
  • If customer elects to not set up a pre-paid balance and they reach their monthly excessive usage limit, their PSTN services is suspended for the remainder of the month.

Payment model:

  • Account balance is drawn down as services are consumed.
  • Customer can select their EA Enrollment as a payment instrument in the Office 365 Portal.
  • Each time a customer’s balance reaches the minimum threshold, a replenishment of funds is triggered at which time the customer is invoiced.

Billing and reporting:

  • Consumption billing charges appear as a line item on the EA Invoice as Skype for Business PSTN Consumption.
  • Usage reports are available in the Admin Center at any time.
  • Customers without an EA can set up an account with a credit card or invoicing payment model.

Yes. Usage reporting will be available via the Skype for Business Admin Center.

In addition, you can restrict usage to certain users if they are at risk of exceeding their monthly tenant-pooled limits.

Yes, you can assign users phone numbers directly through the Skype for Business Admin Center. For more information, see Getting phone numbers for your users. If your users already have phone numbers assigned by another provider, you can transfer those existing phone numbers from your service provider or phone carrier.

You can also add up to 10 percent more numbers in addition to what you have licenses for. For example, if you purchase 100 licenses, you can acquire up to 110 new telephone numbers.

Note: the above applies only to acquiring NEW phone numbers through Office 365 and Skype for Business; there is no limit on porting in telephone numbers to our service; if you own the telephone number, you can port in any quantity of telephone numbers regardless of the number of licenses you have.

Yes, there will be a self-service form on the Office 365 Admin portal. Customers who have more than 150 users can engage with a FastTrack engineer to assist with the process.

For additional information, see Transfer phone numbers over to Skype for Business Online.

Yes, you can make and receive phone calls using Skype for Business IP phones, PCs, and mobile devices. For additional information, see Supported phones for Skype for Business Online.

If you have PSTN Consumption billing enabled, you can pay per minute for international calls. Otherwise, the international call will not connect.